Lawful Interception And Data Retention Of Messages

ABSTRACT

A method of configuring a messaging gateway to operate as an Intercepting Control Element or a Data Retention source. The method comprises the steps of receiving, at the messaging gateway, a source message addressed to a recipient and coded in a first format, converting the source message into a destination message, coded in a second format, and generating interception information data including information referred to both the source message and the destination message.

TECHNICAL FIELD

The present invention relates to Lawful Interception and Data Retentionsystems, in particular to systems and method of interception of messagesthat may require format conversion or partial change of content whentransferred from a sender to a receiver.

BACKGROUND

In many countries operators and Internet service providers are todayobliged by legal requirements to provide stored traffic data generatedfrom public telecommunications and Internet services for the purpose ofdetection, investigation and prosecution of crime and criminal offences,including terrorism.

Usually a public official, for instance a judge, is in charge ofauthorizing investigation on target persons, allowing to activate lawfulinterception on their communications or to query on data retentiondatabases. The authorization paper is conventionally referred to as a“warrant”, which is provided to lawful enforcement agencies.

According to a received warrant, the lawful enforcement agency (LEA) mayset targets of interception and/or query data retention databases.

Messages that are object of interception or retention are managedthrough an architecture, referred to as messaging architecture, thatallows users to exchange information irrespectively of the underlyingtechnology and/or of the recipient's capabilities.

Such architecture may comprise a plurality of messaging servers, adispatcher and a message store. Each server may be specific to a kind ofapplication, for instance SMS, MMS, voice-mail, email, and so on. Thedispatcher is in charge of routing information by selecting whichmessaging server should be used to deliver a message, according torecipient's preferences or capabilities. The message store may be a fileserver configured to temporarily host user messages, for instancethrough a mailbox folder.

This kind of architecture allows messages to flow transparently from thesender to the receiver, even if the receiver is not able to receive theoriginal message in the format intended by the sender. For instance, theoriginal message may be an MMS message directed to a recipient that isnot able to receive MMS messages but, for example, only SMS messages.

In that case, the dispatcher may check the recipient's capabilities andmay direct the SMS messaging server to convert the original MMS messageinto an SMS message, so that a message, though in converted form, can bedelivered to the recipient.

A conventional architecture for Lawful Interception (LI) comprises anIntercepting Control Element (ICE) providing the user equipment of thetarget user with an access to the telecommunications network

Problems with existing solutions occur when, as in the above example, amessage must be converted and/or stripped of part of its content, suchas when an MMS is converted into an SMS, to be delivered to therecipient.

If the recipient is the target user of a Lawful Interception system, theoriginal message may contain richer information than it is contained inthe converted message, which converted message, in current systems,represents the object of interception.

It would be desirable not to lose the richer information contained inthe original message, which could be relevant for lawful interceptionpurposes.

SUMMARY

Aim of the present invention is to overcome the above drawbacksaffecting the prior art. Within this aim, object of the invention is toimprove current interception systems to provide law enforcement agencieswith more comprehensive information without substantially affectingperformance of the telecommunications network.

This aim and other objects which will become better apparent hereinafterare achieved by a method for providing law enforcement agencies in atelecommunications network with interception or retention data relatedto a target user, which comprises the step of configuring a messaginggateway to operate as an Intercepting Control Element or as a DataRetention source.

According to a first aspect of the invention, the messaging gateway mayreceive a source message addressed to a recipient and coded in a firstformat, convert the source message into a destination message, coded ina second format, to be sent to the recipient, and generate interceptioninformation data including information referring to both the sourcemessage and the destination message.

The method may further comprise the preliminary step of provisioning awarrant to the messaging gateway, to initiate interception on the targetuser.

The generation of interception information data may include thegeneration of Intercept Related Information and Content ofCommunication; the generation of Content of Communication may involvethe generation of first information related to the source message and ofsecond information related to the destination message.

The selective generation of the first or the second information may becarried out according to a content of the warrant.

The interception information data may be converted into a formatrequested by law enforcement agencies.

The above aim and objects are also achieved by a Lawful Interceptionsystem for interception or retention of data related to a target user ina telecommunications network, which comprises one or more messaginggateways configured to operate as Intercepting Control Elements or DataRetention sources.

The messaging gateway may be configured to operate as an InterceptingControl Element or as a Data Retention source for a Lawful Interceptionsystem. In one embodiment, the messaging gateway may be an EnrichedMessaging Gateway.

According to a further aspect of the invention, the aim and objects ofthe invention are also achieved by a telecommunications networkcomprising a Lawful Interception system which includes a messaginggateway configured to operate as an Intercepting Control Element or as aData Retention source.

The messaging gateway may be configured to operate as InterceptingControl Element or Data retention source operable in a LawfulInterception system or with a Data Retention System by loading acomputer program.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will becomebetter apparent from the detailed description of particular but notexclusive embodiments, illustrated by way of non-limiting examples inthe accompanying drawings, wherein:

FIG. 1 is a Lawful Interception system according to an embodiment of theinvention;

FIG. 2 is an arrangement of a service provider with Data Retention (DR)capabilities;

FIG. 3 shows a Messaging Architecture according to the invention;

FIG. 4 shows the operation of the Lawful Interception management systemaccording to a preferred embodiment of the invention;

FIG. 5 shows the operation of the Data Retention management systemaccording to a preferred embodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 shows a Lawful Interception (LI) system 1 for accessingcommunications related data according to an embodiment of the invention.

Lawful Interception system 1 comprises a Messaging Gateway 11 adapted toissue Intercept Related Information and Content of Communicationinvolving target users.

Lawful Interception system 1 may further comprise one or more LawEnforcement Monitoring Facilities (LEMFs) 12, through which respectiveLEAs may receive interception information.

An Administration Function (ADMF) entity 13 may be configured forsending target identity and LI authorization data from the LEAs to theMessaging Gateway 11. ADMF 13 may interface through a first HandoverInterface 14 (HI 1) with all the LEAs that may require interception inthe intercepting network, while keeping intercept activities ofindividual LEAs separate and interfacing to the intercepting network.ADMF 13 may also be used to hide from the Messaging Gateway 11 thatmultiple activations by different LEAs on the same target may be inplace. ADMF 13 may also be partitioned to ensure separation of theprovisioning data from different agencies.

Messaging Gateway 11 may be linked to ADMF 13 by means of its ownX1_(—)1 interface, in order to perform interception, includingactivation, deactivation, interrogation as well as invocation,independently from other messaging gateways that may be present in thenetwork.

In order to deliver the intercepted information to the LEAs, twoDelivery Functions (DF) entities may be provided, each exchangingrespective portions of information with ADMF 13, through X1_(—)2 andX1_(—)3 interfaces, and LEMF 12.

In particular, a DF2 entity 15 may be configured to receive InterceptRelated Information (IRI) from the Messaging Gateway 11, through an X2interface, and to convert and distribute the IRI to the relevant LEAsvia a second Handover Interface 16 (HI2) by means of a MediationFunction (MF) 17.

The IRI is a collection of information or data associated withtelecommunication services involving the target identity, such as callassociated information or data, e.g. unsuccessful call attempts, serviceassociated information or data, e.g. service profile management bysubscriber, and location information.

A DF3 entity 18 may be configured to receive Content of Communication(CC) information from Messaging Gateway 11 through an X3 interface, andto convert and distribute such information to the relevant LEA throughan MF 19 and a third Handover Interface 20 (HI3).

FIG. 2 shows another embodiment of the invention, with reference to aData Retention (DR) System 2 in a Communication Service Provider 21(CSP). Specifically, CSP 21, which incorporates Messaging Gateway 11, isprovided with a Data Retention (DR) System 23 for exchanging retaineddata relating information with a Requesting Authority 24, which may be aLaw Enforcement Agency (LEA).

The data exchanged between CSP 21 and Requesting Authority 24 maycomprise requests from Requesting Authority 24, corresponding responsesfrom the DR system and other DR information, such as results of requestsand acknowledgments of receipt. CSP 21 and DR system 23 exchange theabove data with the Requesting Authority via Handover Interfaces.

A generic Handover Interface may adopt a two-port structure in whichadministrative request/response information and Retained DataInformation are logically separated. In particular, a first HandoverInterface port HI-A 25 may be configured to transport various kinds ofadministrative, request and response information from/to the RequestingAuthority 24 and an organization at the CSP 21 that is responsible forRetained Data matters, identified by an Administration Function 27.

The Requesting Authority 24 may use Handover Interface HI-A 25 to handover the requests for the retained messaging data towards the DataRetention System 23.

A second Handover Interface HI-B 26 may be configured to transport theretained data information stored in a repository 29 from CSP 21 toRequesting Authority 24.

The individual retained data parameters may be sent to RequestingAuthority 24 at least once, if available. To this aim, aMediation/Delivery function 28 may be provided, for retrieving theretained data from the repository 29 and forward such data to theRequesting Authority 24 in a suitable format through the HI-B 26.

FIG. 3 shows a Messaging Architecture according to an embodiment of theinvention.

Messages flow in the network according to the flow diagram depicted inFIG. 3, where group 33 represents a plurality of messaging servers, eachimplementing a specific messaging service. Messaging servers may includeVoice Mail servers 34, MMS servers 35, Email servers 36, SMS servers 37,and any other kind of servers 38 according to requirements.

For sake of clarity, groups 33 and servers 34, 35, 36, 37 and 38 areshown twice at the two sides of a communication, in order to representboth the incoming and the outgoing side of a message flow.

When a message is received by a corresponding messaging server at theincoming side, the messaging server runs its conventional businesslogic, for instance by validating the user and screening the message forvirus content.

The messaging server then queries Dispatcher 31 in Messaging Gateway 11for instructions on how the message should be routed to the recipient.The Dispatcher 31 thus acts as a route resolver, determining whichmessaging server should be used to deliver the message, for instance bychecking recipient's capabilities or preferences. Dispatcher 31 may thenreply with an indication of the preferred routing.

Every user may have a mailbox in Message Store 32, which acts as arepository in connection with Messaging Gateway 11 to hold user relatedmessages. The mailbox may contain subordinate folders such as, forinstance, an inbox and an outhox. Messaging Gateway 11 may thus storethe incoming message in the recipient's inbox within Message Store 32,while Dispatcher 31 determines in which form the message should bedispatched.

Dispatcher 31 may schedule an event related to the delivering of themessage. When the messaging server receives acknowledgment fromDispatcher 31 that the dispatcher has taken over the responsibility fordelivering the message, the Messaging Server signals the sender that themessage has been accepted and will be delivered. The Messaging Server,at the incoming side, has now completed its task.

In one embodiment the message may be delivered directly by the MessagingServer, without storing it in Message Store 32.

When the event scheduled by Dispatcher 31 is triggered, Dispatcher 31selects a messaging server capable of handling a message to therecipient in the previously determined format, and asks it to deliverthe message.

The selected Messaging Server, at the outgoing side, begins the processof message delivery. The message is fetched from the recipient's inboxin Message Store 32 and delivered to the recipient.

FIG. 4 refers to a Lawful Interception management system according to anembodiment of the invention, for recovering the information about bothan original and a converted message.

At step 43, LEMF 12 sends an activation request to ADMF 13 for aninterception on target user 42, referred to as User B. According to thisrequest, at step 44 ADMF 13 may activate a warrant in Messaging Gateway11.

A source message 45 intended to be sent from a sender 41, referred to asUser A, to target user 42 arrives at Messaging Gateway 11.

Dispatcher 31 verifies whether the format of the source message iscompatible with the capabilities of target user 42. In case the sourcemessage is in a format that cannot be received by target user 42, forinstance because target user 42 subscribes to a less advanced ordifferent messaging service, at step 46 the message is converted intodestination message 47. If necessary, part of the content of sourcemessage 45 may be discarded. For instance, if source message 45 is anMMS message containing a picture, such picture cannot be transferred toa target user 42 if target user 42 is only able to receive an SMS.However, even if User B 42 is capable of receiving messages encoded inthe format selected by User A 41, User B 42 may require that a messageis in any case converted and delivered in a different format.

No message conversion occurs if the message is to be forwarded to targetuser 42 in the same format provided by sender 41.

At next step, destination message 47, which indicates the message afterconversion, is delivered to User B 42. User B 42 may be warned in thesame or in a separate message that source message 45 was convertedand/or that part of its content has been discarded.

Messaging Gateway 11 may generate and send Intercept Related InformationIRI 48 to DF2 15, including information referred to both source message45 and destination message 47.

At step 49, DF2 15 may convert IRI 48 into a required standard format.Relevant information is then transferred to LEMF 12.

Messaging Gateway 11 may also generate Content of Communication. In thiscase, the information may be divided over different CC messages, inparticular over a first CC message 50 referred to the source message 45and a second CC message 51 referred to destination message 47.

Such different CC messages 50 and 51 may be passed to DF3 18. At steps52 and 53, DF3 18 may convert the first CC message 50 and the second CCmessage 51 into a required or standard format, before forwarding thesepieces of information to LEMF 12.

The content of a warrant may trigger a choice to send LEMF 12information related to the content of original message 45 only,information related to the content of converted message 47 only, orinformation related to the content of both source and destinationmessages.

FIG. 5 refers to the Data Retention management system according to anembodiment of the invention, arranged to allow recovering of informationrelated to both an original and a converted message.

When a source message 63 intended to be sent from a sender 41, referredto as User A, to target user 42 arrives at Messaging Gateway 11,Dispatcher 31 verifies whether the format of the source message iscompatible with the capabilities of target user 42. In case the sourcemessage is in a format that cannot be received by target user 42, forinstance because target user 42 subscribes to a less advanced ordifferent messaging service, at step 64 the message is converted intodestination message 65. If necessary, part of the content of sourcemessage 63 may be discarded. For instance, if source message 63 is anMMS message containing a picture, such picture cannot be transferred toa target user 42 if target user 42 is only able to receive an SMS.However, even if User B 42 is capable of receiving messages encoded inthe format selected by User A 41, User B 42 may require that a messageis in any case converted and delivered in a different format.

Destination message 65 is then delivered to User B 42.

FIG. 5 shows that Messaging Gateway 11 provides Message Data Records 66,including conversion information, to Data Retention System MediationFunction/Delivery Function 28.

Data Records After Mediation 67 may be transferred from DRS MF/DF 28 andstored in Data Retention System Storage 29. The information stored inData

Retention System Storage 29 may comprise information indicating thatsource message 63 as sent by sender 41 has been converted to destinationmessage 65 before reaching target user 42.

Steps 63 through 67 may be executed for any incoming message.

Any moment in time, LEA 24 may submit (step 68) a request to query thedata retention database for retrieving information concerning targetuser 42. The query may be received by ADMF 27 and passed on to DataRetention System Mediation Function/Delivery Function 28 through DRSStorage 29.

At step 69, DRS MF/DF 28 delivers the results of the query to LEA 24,through HI-B 26. The requested data may include information concerningmessage conversion from source message 63 to destination message 65.

Law Enforcement Agencies can thus query the database containing retaineddata and access information indicating both the kind of format of theoriginal message, as intended by the sender, and the kind of format ofthe destination message, as actually received at the recipient's side.

According to a preferred embodiment, Messaging Gateway 11 is an EnrichedMessaging Gateway (EMG) as known in the art, containing lightweightmessaging servers that provide a suite of interfaces. Lightweightmessaging servers may support several network-to-network interfaces(NNI), with associated business logic.

Messaging events may be captured and stored in a Messaging EventRepository (MER). When a subscriber sends or receives a message, forinstance MMS, SMS, instant messaging, voice-mail and e-mail messages,EMG 11 may record the specific messaging events in a Charging DataRecord (CDR). The triggering events may be based on the incoming andoutgoing events that EMG 11 records as the message is processed betweenthe originating and terminating subscribers 41, 42.

Each triggering point may be based on a combination that consists of an<operation> and an <event>.

For an incoming message, a class named <OrigClass> represents themessage class of the originating message arriving at EMG 11 as definedby in the message header, for example SMS.

For outgoing message operations, the pair <OrigClass>-<DestClass> mayrepresent the originating message class and destination message classdefined in the message header, for example SMS-IM. The operation needsto identify both ends of the transaction, so that the CDR contains allthe data that the operator may require to bill the appropriatesubscriber.

Table 1 describes the operations and events that make up the triggeringpoint used to generate CDR data, as applicable to the instant invention.The trigger points apply to all types of messages handled by EMG.

TABLE 1 Operation Event Description <OrigClass> Incoming.ok A messagehas been received and stored successfully <OrigClass> Incoming.failed Amessage has been received but could not be handled by EMG and thereforerejected <OrigClass>- Outgoing.ok A message has been delivered<DestClass> successfully through one of EMG outgoing interfaces<OrigClass>- Outgoing.failed A message has failed to be delivered<DestClass> <OrigClass>- Outgoing.expired A message has expired<DestClass>

When a message trips one of the triggering points in EMG, the followingCDR output may be generated, both in the case of successful orunsuccessful event. CDRs may be generated for all successful receptionof SMS messages as follows:

<Ericsson.operation name=“sms”> <Ericsson.event name=“Incoming.ok”><Ericsson.party-to-charge name=“None”> <Ericsson.action name=“CDR”/></Ericsson.party-to-charge> </Ericsson.event> </Ericsson.operation>

An example of unsuccessful delivery CDR for “SMS-IM” may be as follows:

<Ericsson.operation name=“sms-im”> <Ericsson.eventname=“Outgoing.failed”> <Ericsson.party-to-charge name=“None”><Ericsson.action name=“CDR”/> </Ericsson.party-to-charge></Ericsson.event> </Ericsson.operation>

EMG 11 forwards the CDR to a Message Event Repository (MER). The MERcomponent may be located on a so called Radius server. Therefore, toensure that MER can receive the CDRs, the IP and port of the Radiusserver connecting to EMG should he defined.

The operator can download CDRs from MER over an FTP connection. A CDRmay contain a set of fields for storing message data that can be used bythe operator to bill the customer. The information stored in thesefields may be based on a set of Radius and Vendor (operator) specificattributes described in the following tables. Attributes designated asmandatory should be defined to capture key information required forgenerating a CDR.

Table 2 describes Radius attributes according to an exemplary embodimentof the invention along with a listing of their associated ASN.1 andASCII tag IDs.

TABLE 2 ASN.1 ASCII Manda- Field Description Value Tag Type tory MessageID The generated 1 mi String Yes message ID EMG-NAS-Port The 5 po NumberRadiusAccess serverport Class The class 25 cl String subscriptionOriginator “From” field 31 cg String EMG-NAS- TN ID 32 ni String YesIdentifier Account-Status- Start/Stop 40 ty Number Type indicator CDR-The unique 44 id String Yes Transaction- Accounting ID Id

Table 3 lists the operator specific attributes that may be included inthe CDR. These attributes may be packed as a sequence ofVendor-Type/Vendor-Length/Value triples, following the initial Type,Length and Vendor-ID fields.

TABLE 3 ASN.1 ASCII Field Description Value Tag Type MandatoryLayer-Specific- The EMG product indicator 0 it Number AttributeMessage-Type Type of message 1 et Number Yes Destination “To” field 2 deString Yes Message-Size Size of message 3 sz Number Duration-of-StorageThe difference between 4 ds Number reception and delivery or expirationtime Delivery-Time The time when the message 6 dt Time is successfullydelivered Submission-Time The time when the message 7 st Time isreceived in the EMG Expiration-Time Time the message is going 8 ex Timeto expire Message-Priority The priority of message 9 mp NumberMessage-Content Message content type 11 mo String EMG-S-Identifier EMGsystem name 14 in String Yes CDR-Record-Type The destination directionof 15 rt String Yes message and the interface it uses Event-DispositionThe reason why the 19 ed Number Yes charging event occurs GMT-Offset Thedifference between 41 go String local and Greenwich time in secondsTrigger-Point The trigger point defined in 42 tp String theconfiguration file Original-Message- Size of original received 44 osNumber Size message Service-Correlation- The Id used to correlate 61 siString Id charging information between EMG and the sending/receivingnodes Number-Of- The number of received or 62 nm Number Messages sentmessages for stored MFS message

A MER component may receive and store event messages from othercomponents in the system and produce Charging Data Records (CDRs). TheseCDRs can then be used for billing or statistical purposes. The CDRs maybe stored in files in an ASCII repository, stored in files in anASN.1/BER repository, or transferred directly to an external serverusing the RADIUS Accounting protocol.

In order to apply the invention in the context of 3GPP, ETSI and ANSIstandards for the handover interfaces and for the interception domain,main parameters for HI2 16 and HI3 20 can be used as shown in Tables 4and 5, respectively.

TABLE 4 Message attributes Description Message-Type e.g. sms, mms,e-mail, im, voice-mail, fax, . . . Message-Event-Type e.g. send, store,retrieve, login, logout, invite to messaging, join, leave, . . .Message-Event disposition e.g. modified, stripped out, copied, . . .Message-Sender e.g. text, MSISDN, e-mail address, IP address, . . .Message-Recipients Sequence of recipient info e.g. text, MSISDN, e-mailaddress, IP address, . . . Protocol e.g. HTTP, WSP, SMPP, SMTP, IMAP4,POP3, . . . Time Of Event Date and Time of the message event MessageContent Text, Voice, Video, Image, Binary, . . . Message Size Size ofmessage (in octets) . . .

TABLE 5 Message attributes Description Message-Format e.g. IP-packet,application Original-content Original message content beforemodification Modified-content Message content after conversion . . .

With regard to Data Retention, a Handover Interface may be enhanced asshown in Table 6 to deliver to requesting LEA 24 results includingconversion information as originated by Enriched Messaging Gateway 11.

TABLE 6 Message attributes Description Message Event disposition e.g.modified, stripped out, copied, . . . Message Type Multimedia Message,Instant message, Group message, . . . Original Message Content e.g. textand video Modified Message Content e.g. text Original Message SizeOriginal Size of message (in octets) Modified Message Size Size ofmessage after conversion(in octets) Client Type e.g. PC, laptop, . . .

It has been thus shown that the invention fully achieves the intendedaim and objects, since it gives the possibility to know the content ofan original message, for interception purposes, even if the target userhas received a converted message with a different amount of informationthan contained in the original message.

Clearly, several modifications will be apparent to and can be readilymade by the skilled in the art without departing from the scope of thepresent invention. Even though the exemplary embodiments have beendiscussed indicating the recipient as the target of interceptionactivity, the same description and considerations apply if the targetuser is sender 41.

Therefore, the scope of the claims shall not be limited by theillustrations or the preferred embodiments given in the description inthe form of examples, but rather the claims shall encompass all of thefeatures of patentable novelty that reside in the present invention,including all the features that would be treated as equivalents by theskilled in the art.

Where technical features mentioned in any claim are followed byreference signs, those reference signs have been included for the solepurpose of increasing the intelligibility of the claims and accordingly,such reference signs do not have any limiting effect on theinterpretation of each element identified by way of example by suchreference signs.

1. A method for providing law enforcement agencies (12, 24) in atelecommunications network with interception or retention data relatedto a target user (41, 42), comprising the step of configuring amessaging gateway (11) to operate as an Intercepting Control Element ora Data Retention source.
 2. The method according to claim 1, comprisingthe steps of: at the messaging gateway (11), receiving a source message(45, 63) addressed to a recipient and coded in a first format;converting said source message (45, 63) into a destination message(47,65), coded in a second format, to the recipient; generatinginterception information data (48, 50, 51, 66) including informationreferring to both the source message (45, 63) and the destinationmessage (47, 65).
 3. The method according to claim 1 or 2, comprisingthe step of provisioning a warrant to said messaging gateway (11) toinitiate interception on a target user (41, 42).
 4. The method accordingto claim 2 or 3, wherein the step of generating interception informationdata comprises generating Intercept Related Information (48) and Contentof Communication (50, 51).
 5. The method according to claim 4, whereinthe step of generating Content of Communication comprises generatingfirst information (50) related to said source message (45) and secondinformation (51) related to said destination message (47).
 6. The methodaccording to claim 5, comprising selectively generating said firstinformation (50) or said second information (51) according to a contentof said warrant.
 7. The method according to any of claims 2 to 6,further comprising the step of converting said interception informationdata (48, 50, 51, 66) into a format requested by law enforcementagencies (12, 24).
 8. A Lawful Interception system (1, 2) forinterception or retention of data related to a target user (41, 42) in atelecommunications network, the system comprising one or more messaginggateways (11) configured to operate as Intercepting Control Elements orData Retention sources.
 9. A messaging gateway (11) configured tooperate as Intercepting Control Element for a Lawful Interception system(1) according to claim
 8. 10. A messaging gateway (11) configured tooperate as Data Retention source for a Lawful Interception system (2)according to claim
 8. 11. The messaging gateway (11) according to claim9 or 10, wherein said messaging gateway (11) is an Enriched MessagingGateway.
 12. A telecommunications network comprising a LawfulInterception system (1, 2) according to claim
 8. 13. A computer programloadable into a messaging gateway (11) to configure said messaginggateway (11) as Intercepting Control Element or Data retention sourceoperable in a Lawful Interception system (1, 2) according to claim 8.